Relativity of Mass: Mass Can Decrease With Velocity

Asutosh Kumar*

Received : April 24, 2026 | Published : May 26, 2026

Citation: A. Kumar, “Relativity of Mass: Mass Can Decrease With Velocity,” Phys. J. Theor. Exp. Stud. 2(2), 1–10 (2026). DOI: 10.64978/pjtes.2026.0526007

License: This article is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0) , which permits use, sharing, adaptation, distribution, and reproduction in any medium or format, provided appropriate credit is given to the original author(s) and the source, a link to the Creative Commons licence is provided, and any changes made are indicated.

Abstract

We present a simple approach for deriving velocity-dependent masses using the principle of relativity. Our analysis reveals that the transformations associated with Galilean, Lorentz, and other space-time frameworks between two inertial reference frames are fundamentally equivalent in the context of the relativity of mass. Consequently, the notion of velocity-dependent mass is not the exclusive characteristic of Special Relativity (Lorentz transformation). Among the notable conclusions drawn from our formalism are: mass can both increase and decrease with velocity, a particle can never be completely at rest, and superluminal signaling is in principle feasible. Furthermore, we discuss on the nature of mass and argue that a photon is not massless.

Keywords: Relativity of mass; velocity-dependent mass; mass can decrease with velocity; superluminal signaling; photon mass; rest mass vs intrinsic mass